Mismatch repair cancer syndrome
Cancer syndrome
From Wikipedia, the free encyclopedia
Mismatch repair cancer syndrome (MMRCS) is a cancer syndrome associated with biallelic DNA mismatch repair mutations.[1] It is also known as Turcot syndrome (after Jacques Turcot, who described the condition in 1959) and by several other names.[1]
In MMRCS, neoplasia typically occurs in both the gut and the central nervous system (CNS).[1] In the large intestine, multiple colonic polyps develop; in the CNS, brain tumors.
Genetics
Under the name constitutional mismatch repair-deficiency (CMMR-D), it has been mapped to MLH1, MSH2, MSH6 or PMS2.[2] Monoallelic mutations of these genes are observed in the condition known as Lynch syndrome or hereditary nonpolyposis colorectal cancer, while biallelic mutations are observed in CMMR-D.[3] People expressing the HNPCC (which itself is considered autosomal dominant) trait are considered carriers of CMMR-D, thus CMMR-D is classified as autosomal recessive.[citation needed]
The term "childhood cancer syndrome" has also been proposed.[4][5] Café-au-lait macules have been observed.[6]
Diagnosis
Childhood to early adult onset HNPCC + malignant gliomas.[clarification needed] The polyps developed tend to be larger, fewer, and progress to malignancy earlier than those seen in familial adenomatous polyposis,[1] a clinically similar condition with different underlying mutations. Diagnostic testing consists of a blood sample being collected, and a genetic specialist compares two copies of a patient's gene to normal MMR genes. If there are differences in the genes, the specialists are able to further test and decide if the patient has the deficiency.[7]
History
OMIM currently includes "Turcot syndrome" under "mismatch repair cancer syndrome". Turcot syndrome is the association between familial polyposis of the colon and brain tumors[8] like medulloblastoma or malignant glioma. It was first reported by Canadian surgeon Jacques Turcot (1914–1977 ) et al. in 1959 and hence carries the first author's name.[9]